org.apache.commons.collections4.functors
Class SwitchClosure<E>

java.lang.Object
  extended by org.apache.commons.collections4.functors.SwitchClosure<E>
All Implemented Interfaces:
Serializable, Closure<E>

public class SwitchClosure<E>
extends Object
implements Closure<E>, Serializable

Closure implementation calls the closure whose predicate returns true, like a switch statement.

Since:
3.0
Version:
$Id: SwitchClosure.java 1479337 2013-05-05 15:20:59Z tn $
See Also:
Serialized Form

Constructor Summary
SwitchClosure(Predicate<? super E>[] predicates, Closure<? super E>[] closures, Closure<? super E> defaultClosure)
          Constructor that performs no validation.
 
Method Summary
 void execute(E input)
          Executes the closure whose matching predicate returns true
 Closure<? super E>[] getClosures()
          Gets the closures.
 Closure<? super E> getDefaultClosure()
          Gets the default closure.
 Predicate<? super E>[] getPredicates()
          Gets the predicates.
static
<E> Closure<E>
switchClosure(Map<Predicate<E>,Closure<E>> predicatesAndClosures)
          Create a new Closure that calls one of the closures depending on the predicates.
static
<E> Closure<E>
switchClosure(Predicate<? super E>[] predicates, Closure<? super E>[] closures, Closure<? super E> defaultClosure)
          Factory method that performs validation and copies the parameter arrays.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SwitchClosure

public SwitchClosure(Predicate<? super E>[] predicates,
                     Closure<? super E>[] closures,
                     Closure<? super E> defaultClosure)
Constructor that performs no validation. Use switchClosure if you want that.

Parameters:
predicates - array of predicates, cloned, no nulls
closures - matching array of closures, cloned, no nulls
defaultClosure - the closure to use if no match, null means nop
Method Detail

switchClosure

public static <E> Closure<E> switchClosure(Predicate<? super E>[] predicates,
                                           Closure<? super E>[] closures,
                                           Closure<? super E> defaultClosure)
Factory method that performs validation and copies the parameter arrays.

Type Parameters:
E - the type that the closure acts on
Parameters:
predicates - array of predicates, cloned, no nulls
closures - matching array of closures, cloned, no nulls
defaultClosure - the closure to use if no match, null means nop
Returns:
the chained closure
Throws:
IllegalArgumentException - if array is null
IllegalArgumentException - if any element in the array is null

switchClosure

public static <E> Closure<E> switchClosure(Map<Predicate<E>,Closure<E>> predicatesAndClosures)
Create a new Closure that calls one of the closures depending on the predicates.

The Map consists of Predicate keys and Closure values. A closure is called if its matching predicate returns true. Each predicate is evaluated until one returns true. If no predicates evaluate to true, the default closure is called. The default closure is set in the map with a null key. The ordering is that of the iterator() method on the entryset collection of the map.

Type Parameters:
E - the type that the closure acts on
Parameters:
predicatesAndClosures - a map of predicates to closures
Returns:
the switch closure
Throws:
IllegalArgumentException - if the map is null
IllegalArgumentException - if any closure in the map is null
ClassCastException - if the map elements are of the wrong type

execute

public void execute(E input)
Executes the closure whose matching predicate returns true

Specified by:
execute in interface Closure<E>
Parameters:
input - the input object

getPredicates

public Predicate<? super E>[] getPredicates()
Gets the predicates.

Returns:
a copy of the predicates
Since:
3.1

getClosures

public Closure<? super E>[] getClosures()
Gets the closures.

Returns:
a copy of the closures
Since:
3.1

getDefaultClosure

public Closure<? super E> getDefaultClosure()
Gets the default closure.

Returns:
the default closure
Since:
3.1


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